Hypernuclei and Experimental Determination of the Hyperon-Nucleon Potentials

1
Hypernuclei and Experimental Determination of
the Hyperon-Nucleon Potentials

• Take R. Saito
• Gesellschaft f?r Schwerionenforschung (GSI),
• A research center of Helmholtz Association
• and
• Johannes Gutenberg-Universität Mainz

2
Strangeness production in neutron starsOutline
of this talk

• When two nucleons are touching to each other
• ( 1 fm distance)
• Mass density 140 MeV fm-3
• Mass of strange (s)-quark
• 150 MeV
• Transformation u and d-quarks ? s-quarks
• Hyperons (Y)
• In the core of neutron stars
• neutron (n, udd) ? L (uds)
• NL and LL interactions
• Electron condensation with very large Fermi
  energies
• ? gains for negative Y
• S- (dds) SN interaction in neutron dense matter
  is repulsive
• X- (dss) XN interaction
• Kaon condensations Deeply kaonic bound nuclei
• H-dibaryons

F. Weber, J. Phys G 25(1999)R195
3
How to study baryon interactions

• Nuclear reaction experiment
• Reaction cross section, spin-dependent
  interactions
• Nuclear target Nucleons (N)
• Nuclear beams Nucleons (N)
• NN interactions
• Nuclear structure
• Nuclear potential, mean field, shell structures
• Nuclear target and nuclear beams.
• NN interactions

4
How to study YN and YY interactions

• No hyperon target available
• No hyperon beam available
• No reaction experiment possible so far
• However, hyperon can be bound in nuclei
• For example, 7LLi
• Total mass 7, 3 protons, 3 neutrons, 1 L
• Hypernuclei
• Micro-laboratory with protons, neutrons and
  hyperons.
• YN and YY interaction can be investigated !!!

5
Hypernucler activities

• PANDA at FAIR
• 2012
• Anti-proton beam
• Double L-hypernuclei
• g-ray spectroscopy

• BNL
• K- beams
• Single L-hypernuclei

• HypHI at GSI/FAIR
• Heavy ion beams
• Single L-hypernuclei at extreme isospins
• Magnetic moments

• KaoS, MAMI C
• 2007
• Electro-production
• Single L-hypernuclei

• J-PARC
• 2009
• Intense K- beam
• Single and double L-hypernuclei
• g-ray spectroscopy for single L

• JLab
• 2006
• Electro-production
• Single L-hypernuclei

• FINUDA at DAFNE
• ee- collider
• Stopped-K- reaction
• Single L-hypernuclei
• g-ray spectroscopy

• KEK
• p beams
• Single L-hypernuclei
• Double L-hypernuclei

• CERN
• K- beams
• Single L-hypernuclei

6
LN interactions in neutron matter L-S coupling

• L-S coupling in nuclei
• Coherent L-S coupling
• For hypernuclei away from NZ
• No isospin excitation needed because of non-zero
  isospin of core
• Can be observed in exotic light hypernuclei
• S decay channel of proton/neutron rich
  hypernuclei,
• Magnetic moments of 5LHe, 7LHe, 6LBe and 5LBe.

Coherent part, away from NZ
Incoherent part, NZ
7
Hypernuclei with Heavy Ion Beams The HypHI
project at GSI/FAIR

• Heavy ion induced reaction at relativistic
  energies (heavy-ion collision)
• NN -gt LKN Energy threshold 1.6 GeV
• Heavy ion beams with E gt 1.6 GeV/u needed
• Stable heavy ion beam at GSI
• Stable heavy ion beam at FAIR
• RI-beam from FRS and super-FRS
• Large Lorentz factor g (gt3)
• Effective lifetime Longer by the Lorentz factor
• 200 ps -gt 600 ps with g3
• 200 ps -gt 4 ns with g20
• Only a few light hypernuclei so far identified
  with heavy ion beams at Dubna (3LH and 4LH, 0.2
  mb, with 4He and 7Li beams)

L
8
HypHI at GSI/FAIR Concept of Experiments

• Produced hypernucleus at the similar velocity of
  projectiles
• Large Lorents factor g gt 3
• 200ps -gt 600ps (g3), hypernuclear decay in
  flight
• Example 12C 12C -gt ALZ K,0 X

• Mesonic weak decay
• L -gt p- p
• Non-mesonic weak-decay
• Lp -gt np

Magnet
n
target
L-Hypernucleus
Residues
K
Scintillators diamond Trackers N-detector K
counter
p, p
9
Phase 0 of HypHI

• The goal of the Phase 0 experiments
• To confirm Dubnas hypernuclear production at 2 A
  GeV with 6Li primary beams Mesonic decay L -gt
  p- p
• 3LH -gt p- 3He
• 4LH -gt p- 4He
• 5LHe -gt p- 4He p

10
Estimates
4LH

• Beam 6Li, 107 /s
• Target 12C, 8 g/cm2
• Trigger efficiency with tracking p- TOF 7
• Background reduction by the trigger 0.017
• Trigger rate 340 Hz
• Proposal submitted to the GSI PAC
• Experiment beginning of 2008

11
The HypHI perspective

• HypHI started in 2004
• Spokesperson T.R. Saito (GSI)
• Approved by the Helmholtz-Association in 2006 as
  a Young Investigators Group at GSI
• Phase 0 Feasibility study
• 2008 at GSI, proposal already submitted to the
  GSI PAC
• Phase 1 Proton rich hypernuclei
• Isospin dependence
• LS coupling
• 2008-2011 at GSI
• Phase 2 Neutron rich hypernuclei
• LN interaction in neutron dense matter
• 2012 at FAIR
• Phase 3 Hypernuclear separator
• Hypernuclei at drip-lines
• Hypernuclear magnetic moments

12
The HypHI collaboration

• Giessen University, Germany
• GSI (DVEE, KP2, KP3), Germany
• JINR, Dubna, Russia
• Johannes Gutenberg University Mainz, Germany
• KEK, Japan
• Moscow State University, Russia
• Nara Womens University, Japan
• Niels Bohr Institute, Denmark
• Osaka Electro-Communication University, Japan
• Osaka University, Japan
• Peking University, China
• RIKEN, Japan
• Soltan Institute for Nuclear Studies, Poland
• Tokyo University, Japan
• Tokyo University of Science, Japan
• Tohoku University, Japan
• TRIUMF, Canada
• Still expanding

13
How to Determine X-N PotentialExperiment E05 at
J-PARC

• The depth of XN potential unknown
• It is not known if X can exist in the core of
  neutron stars
• Coupling of X-N ? LL the strength unknown
• If there is large coupling three body force
  through this channel
• If X- is not produced in the core of neutron
  stars
• K- potential in the neutron dense matter is
  important
• K-nn deeply kaonic bound states Kaon
  condensation

14
How to Determine X-N PotentialExperiment E05 at
J-PARC
15
How to Determine X-N PotentialExperiment E05 at
J-PARC

• Spokesperson T. Nagae (KEK/Tokyo Univ.)
• K- beams at 1.8 GeV/c on 12C target (5.4 g/cm2)
• Double strangeness exchange reaction
  12C(K-,K)12XBe
• J-PARC Day-1 experiment
• 200 reconstructed 12XBe per month

16
H-Dibaryon

• LL interaction H-dibaryon (uuddss)
• LL configuration not bound in the free space
• LL-SS-XN coupled configuration could be bound
• LL PANDA and J-PARC
• LL-SS part, LS coupling HypHI
• XN J-PARC
• Search for H-dibaryon state in nuclear matter
• H can be dominant component in the core of
  neutron stars

free H-dibaryon
H-dibaryon in
BLL12.2 MeV
BLL24.0 MeV
T. Yamada, NP A691 (2001) 250c
17
PANDA experiment at FAIR
18
PANDA experiment at FAIR
19
PANDA experiment at FAIR

• Antiproto momentum 1.5 15 GeV/c
• Luminosity 21032 cm-2s-1
• beam diameter 10-100?m
• ?p/p 10-4...310-5

• Charmonium spectroscopy.
• Charmed hybrids, glueballs.
• Precie g-ray spectroscopy of double hypernuclei
  and W-atoms.

injection
septum
electrton cooler
Proton ANtiproton at DArmstadt
circumference 442 m bending power 50 Tm
detector
20
PANDA experiment at FAIR

• Spokesperson J. Pochodzalla (Mainz Univ.)

• Hermetic (4p)
• High rate
• PID (g, e, m, p, K, p)
• Trigger (e, m, K, D, L)
• Compact ()
• Modular

High rate Ge detectors needed!!!
21
Summary

• Contribution from the hypernuclear physics on the
  YN and YY interaction in the core of neutron
  stars
• LN interaction in neutron rich hypernuclei
• LS coupling in neutron dense matter
• XN interaction
• LL interaction
• LL-SS-XN coupling in the nuclear matter
• Spin dependent LN and LL interaction

HypHI at GSI/FAIR
J-PARC
PANDA at FAIR J-PARC
g-spectroscopy at J-PARC, FINUDA. PANDA
Next 10 years the most exciting decade for YN
and YY interactions
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Backups
25
Expanding field
FINUDA at Frascati
J-PARC

• Electroproduction of L-hypernuclei
• Energy resolution lt 1 MeV
• Wavefunction of L-hyperon

CEBAF
Kaos at MAMI C
PANDA at FAIR/GSI
26
Expanding field
FINUDA at Frascati
J-PARC

• Decay of L-hypernuclei
• Non-mesonic weakdecay

CEBAF
Kaos at MAMI C
PANDA at FAIR/GSI
27
Expanding field
FINUDA at Frascati
J-PARC

• Gamma-ray spectroscopy of L-hypernuclei
• Spin-dependent YN interaction

CEBAF
Kaos at MAMI C
PANDA at FAIR/GSI
28
Expanding field
FINUDA at Frascati
J-PARC

• Double L-hypernuclei
• YY interaction

CEBAF
Kaos at MAMI C
PANDA at FAIR/GSI
29
Expanding field
FINUDA at Frascati
J-PARC

• Gamma-ray spectroscopy of double L-hypernuclei
• Spin-dependent YY interaction

CEBAF
Kaos at MAMI C
PANDA at FAIR/GSI
30
Expanding field
FINUDA at Frascati
J-PARC
CEBAF
Kaos at MAMI C
PANDA at FAIR/GSI
31
Expanding field
FINUDA at Frascati
J-PARC

• Difficulties on these experiments
• Direct measurements on hypernuclear magnetic
  moments
• Quark bulding blocks (Qurak Pauli effect and so
  on)
• L/S coupling
• Kaon currents in nuclei
• Hypernuclei away from the b-stability line (at
  extreme isospins), especiaaly for heavy
  hypernuclei
• Isospin dependence on the hyperon wavefunction
• LN interactions
• Very neutron rich hypernuclei (cold neutron
  matter)
• Very proton rich hypernuclei

Heavy ion induced hypernuclear spectroscopy
CEBAF
Kaos at MAMI C
PANDA at FAIR/GSI
32
Why hypernuclei

• Baryons in the core of neutron stars

Baryon-baryon interaction
n (udd) p (uud) L (uds) S (uds)
n N.R. N.R. S.H. S.H.
p N.R. S.H. S.H.
L D.H. D.H.
S D.H.
t 10-10 s
N.N. Nuclear reaction S.H. Single-s
Hypernuclei D.H. Double-s Hypernuclei
33
Heavy Ion Beams Powerful Tools for Hypernuclear
Spectroscopy
34
Heavy Ion Beams Powerful Tools for Hypernuclear
Spectroscopy
FRS
Super-FRS
E gt 1.7 A GeV I gt 105/s
35
Goals of the project

• Hypernuclear magnetic moments
• Quark bulding blockes
• Quark Pauli blocking effect
• L/S coupling as functions of isospins
• Kaon currents in the nuclear matter
• Hypernuclei at extreme isospins
• Cold neutron matter
• L/S coupling
• Long-lived hypernuclear isomer

36
Phase 0 of HypHI

• The goal of the Phase 0 experiments
• To confirm Dubnas hypernuclear production at 2 A
  GeV with 6Li primary beams Mesonic decay L -gt
  p- p
• 3LH -gt p- 3He
• 4LH -gt p- 4He
• 5LHe -gt p- 4He p

37
Accelerator facility at GSI
38
Accelerator facility at GSI
FRS
39
Improved setup for phase 0
Positive charged particles p, d, t, 3He, 4He, 6Li
Negative charged particles p-
40
ALADiN magnet
41
TOF detectors

• TOF-start (new development)
• Polycrystalline diamond detector
• High rate 108 /s
• Excellent time resolution lt 15 ps
• ALADiN TOF wall (existing)
• Plastic scintillator bars
• For negative charged particles (mainly p-)
• Horizontal(x)-vertical(y) tracking
• TOF (new development)
• Plastic scintillator bars
• For positive charged particles
• xy tracking

42
Scintillating fiber arrays

• TR0
• x and y planes
• Energy and time readout
• TR1 and TR2
• x, y and d planes
• Time readout
• Used for tracking triggers

43
Trigger design
TR2
target

• Tracking trigger (K and K0 channel)
• Two types of vertices
• One vertex in the target
• Meson production
• Fragmentation
• Vertex out of the target
• Hypernuclear decay
• Free-L decay
• FPGA/DSP based trigger module
• Efficiency to 4LH events 14

TR1
44
Tracking trigger

• Made with scinitillating fiber trackers
• Secondary vertex behind the target
• Hypernuclear/L decay

500 MHz
T to VME bus
Discriminator card with GSI chip-3
VME Logic module with FPGA and DSP
LVDS
PMT
HAMAMATSU 32 pixels
From Mainz/KaoS collaboration
VME Logic module with FPGA and DSP
VME Logic module with FPGA and DSP
New development at GSI
Tracking trigger
45
New VME logic module

• Purely VME based
• 256 channels I/O
• LVDS
• Fast logic calculations with a large FPGA at 500
  MHz
• Slow complicated calculations by DSP
• Data transfer to the VME bus
• Modules will also be used by the MAMI C KaoS
  experiments

46
p- trigger (hypernuclear decay)

• p- from the target
• Low momentum
• Hitting to the side yoke of the ALADiN magnet
• p- from hypernuclear decays
• Lorentz boosted at g3
• Larger momentum
• Observed by the ALADiN TOF
• Efficiency
• 28 for 4LH events

47
Z2 trigger by TOF

• Z2 particles from the hypernuclear decay
• 3LH -gt 3He p-
• 4LH -gt 4He p-
• 5LHe -gt 4He p p-
• By TOF
• Efficiency
• 95 for 4LH events

48
HypHI Project at GSI/FAIR
2004

• HypHI project started
• LOI and progress report to the GSI PAC, Design
  study
• Design study, preparation for the phase 0
  experiment
• Phase 0 experiment with 3LH, 4LH and 5LHe
• Design study for the setup for hypenuclear
  non-mesonic weak decay measurements
• Phase 1 Experiments for proton-rich hypernuclei
• Phase 2 Experiment for neutron- rich hypernuclei
  at R3B/NuSTAR/FAIR
• Phase 3 Hypernuclear separator
• Hypernuclear magnetic moments
• Hypernuclear drip-lines

2005
2006
2007
2008
2009
2010
2011
49
HypHI Project at GSI/FAIR
Phase 0
2004

• HypHI project started
• LOI and progress report to the GSI PAC, Design
  study
• Design study, preparation for the phase 0
  experiment
• Phase 0 experiment with 3LH, 4LH and 5LHe
• Design study for the setup for hypenuclear
  non-mesonic weak decay measurements
• Phase 1 Experiments for proton-rich hypernuclei
• Phase 2 Experiment for neutron- rich hypernuclei
  at R3B/NuSTAR/FAIR
• Phase 3 Hypernuclear separator
• Hypernuclear magnetic moments
• Hypernuclear drip-lines

2005
gt 103 /week gt 104 /week
2006
2007
2008
2009
2010
2011
50
HypHI Project at GSI/FAIR
Phase 0
2004

• HypHI project started
• LOI and progress report to the GSI PAC, Design
  study
• Design study, preparation for the phase 0
  experiment
• Phase 0 experiment with 3LH, 4LH and 5LHe
• Design study for the setup for hypenuclear
  non-mesonic weak decay measurements
• Phase 1 Experiments for proton-rich hypernuclei
• Phase 2 Experiment for neutron- rich hypernuclei
  at R3B/NuSTAR/FAIR
• Phase 3 Hypernuclear separator
• Hypernuclear magnetic moments
• Hypernuclear drip-lines

2005
gt 103 /week gt 104 /week
2006
Phase 1
2007
2008
2009
2010
2011
51
HypHI Project at GSI/FAIR
Phase 0
2004

• HypHI project started
• LOI and progress report to the GSI PAC, Design
  study
• Design study, preparation for the phase 0
  experiment
• Phase 0 experiment with 3LH, 4LH and 5LHe
• Design study for the setup for hypenuclear
  non-mesonic weak decay measurements
• Phase 1 Experiments for proton-rich hypernuclei
• Phase 2 Experiment for neutron- rich hypernuclei
  at R3B/NuSTAR/FAIR
• Phase 3 Hypernuclear separator
• Hypernuclear magnetic moments
• Hypernuclear drip-lines

2005
gt 103 /week gt 104 /week
2006
Phase 1
2007
2008
2009
2010
Phase 2
2011
52
HypHI Project at GSI/FAIR
Phase 0
2004

• HypHI project started
• LOI and progress report to the GSI PAC, Design
  study
• Design study, preparation for the phase 0
  experiment
• Phase 0 experiment with 3LH, 4LH and 5LHe
• Design study for the setup for hypenuclear
  non-mesonic weak decay measurements
• Phase 1 Experiments for proton-rich hypernuclei
• Phase 2 Experiment for neutron- rich hypernuclei
  at R3B/NuSTAR/FAIR
• Phase 3 Hypernuclear separator
• Hypernuclear magnetic moments
• Hypernuclear drip-lines

2005
gt 103 /week gt 104 /week
2006
Phase 1
2007
2008
2009
2010
Phase 3
2011
53
Hypernuclear separator (Phase 3)

• Hypernuclear production at 20 A GeV at the FAIR
  facility
• Hypernuclei separated by a superconducting magnet

• Hypernuclear magnetic moments
• Hypernuclei toward the nucleon drip-lines

54
Hypernuclear separator (Phase 3)

• Hypernuclear production at 20 A GeV at the FAIR
  facility
• Hypernuclei separated by a superconducting magnet

sweeping magnet
ALADiN
detector for x,y,DE
Sci2
TR2
scintillator barrel
TR1
superconducting magnet
target
1m
TP-MUSIC
to beam dump
collimator
Sci1
Hypernuclear production at 20 A GeV. Carbon or
diamond target, 12g/cm2.
55
Hypernuclear separator (Phase 3)

• Hypernuclear production at 20 A GeV at the FAIR
  facility
• Hypernuclei separated by a superconducting magnet

sweeping magnet
ALADiN
detector for x,y,DE
Sci2
TR2
scintillator barrel
TR1
superconducting magnet
target
1m
TP-MUSIC
to beam dump
collimator
Sci1
4m long superconducting magnet. Separation of
hypernuclei with the collimator.
56
Hypernuclear separator (Phase 3)

• Separation by the 4m 5T magnet
• 6Li 12C at 20 A GeV

57
Hypernuclear separator (Phase 3)

• Hypernuclear production at 20 A GeV at the FAIR
  facility
• Hypernuclei separated by a superconducting magnet

sweeping magnet
ALADiN
detector for x,y,DE
Sci2
TR2
scintillator barrel
TR1
superconducting magnet
target
1m
TP-MUSIC
to beam dump
collimator
Sci1
Removing light hadrons from the hypernuclear
decay before the sweeping magnet.
58
Hypernuclear separator (Phase 3)

• Hypernuclear production at 20 A GeV at the FAIR
  facility
• Hypernuclei separated by a superconducting magnet

sweeping magnet
ALADiN
detector for x,y,DE
Sci2
TR2
scintillator barrel
TR1
superconducting magnet
target
1m
TP-MUSIC
to beam dump
collimator
Sci1
Hypernuclear events reconstruction tagged by
mesonic and non-mesonic weak decay
59
Hypernuclear separator (Phase 3)

• Hypernuclear production at 20 A GeV at the FAIR
  facility
• Hypernuclei separated by a superconducting magnet

sweeping magnet
ALADiN
detector for x,y,DE
Sci2
TR2
scintillator barrel
TR1
superconducting magnet
target
1m
TP-MUSIC
to beam dump

• Precession of the spin distribution of
  hypernuclei.
• Precession angle
• 225 degrees with free-L magnetic moment
• 205 degrees with 8.8 reduction due to the kaon
  exchanging current

collimator
Sci1
60
Hypernuclear separator (Phase 3)

• Hypernuclear production at 20 A GeV at the FAIR
  facility
• Hypernuclei separated by a superconducting magnet

Asymmetric pionic hypernuclear decay Almost 4 p
sr solid angle
sweeping magnet
ALADiN
detector for x,y,DE
Sci2
TR2
scintillator barrel
TR1
superconducting magnet
target
1m
TP-MUSIC
to beam dump

• Precession of the spin distribution of
  hypernuclei.
• Precession angle
• 225 degrees with free-L magnetic moment
• 205 degrees with 8.8 reduction due to the kaon
  exchanging current

collimator
Sci1
61
Rate estimate with the hypernuclear separator
(Phase 3)

• Beam intensity 1010/s at 20 A GeV
• Target 12C, 12 g/cm2
• Reconstruction efficiency in the decay region
  10

62
Hypernuclear landscape

• Essential to study baryon-baryon interaction
  under SU(3)f
• 40/64 vertices can be studied with hypernuclei

63
S-1 sector

• Only 37 L-hypernuclei identified

64
Hypernuclear Physics Born in Europe

• 1952 Danysz and Pniewski, discovery of
  L-hypernuclei with cosmic-rays
• 1952-1970 20 L-hypernuclear events identified
  with cosmic-rays. BL and hints of their decay
• 1970-now Spectroscopy with accelerators
• CERN (upto 1980)
• BNL, KEK (up to 2003), p and K- beams
• Now-
• FINUDA at Frascati
• HKS at CEBAF
• KaoS at MAMI C
• HypHI at GSI/FAIR
• J-PARC
• PANDA at FAIR

65
Coherent L-S coupling
Nucleon has to be isospin excited
Nucleon can remain in the same state
Courtesy of Y. Akaishi
66
Coherent L-S coupling
For example, No coherent L-S coupling in 5LHe
Courtesy of Y. Akaishi
67
Coherent L-S coupling in neutron rich hypernuclei
Courtesy of Y. Akaishi
68
Coherent L-S coupling in neutron stars
Courtesy of Y. Akaishi

• What to be measured with HypHI
• LS coupling amplitude with different isospins
• Magnetic moment of hypernuclei
• p decay due to S coupling at proton rich
  hypernuclei

69
Models of neutron stars
Figure from F. Weber